From 44905ed3959e43f03f9c7345b6799f5805bad7f0 Mon Sep 17 00:00:00 2001
From: Lucas CHOLLET <lucas.chollet@free.fr>
Date: Sun, 30 Apr 2023 19:17:08 -0400
Subject: [PATCH] LibGfx/PortableFormat: Write to the output stream row by row

This is done by adding an intermediate buffer and flush it at the end of
every row. This makes the `add_pixels` method to drop from 50% to 7% in
profiles.
---
 .../ImageFormats/PortableFormatWriter.cpp     | 30 +++++++++++++------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/Userland/Libraries/LibGfx/ImageFormats/PortableFormatWriter.cpp b/Userland/Libraries/LibGfx/ImageFormats/PortableFormatWriter.cpp
index 80b6218bed..018b2e45d1 100644
--- a/Userland/Libraries/LibGfx/ImageFormats/PortableFormatWriter.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/PortableFormatWriter.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "PortableFormatWriter.h"
+#include <AK/FixedArray.h>
 #include <AK/Stream.h>
 
 namespace Gfx {
@@ -31,19 +32,30 @@ ErrorOr<void> PortableFormatWriter::add_header(Stream& output, Options const& op
 
 ErrorOr<void> PortableFormatWriter::add_pixels(Stream& output, Options const& options, Bitmap const& bitmap)
 {
+    if (options.format == Options::Format::Raw) {
+        auto row = TRY(FixedArray<u8>::create(bitmap.width() * 3ul));
+
+        for (int i = 0; i < bitmap.height(); ++i) {
+            for (int j = 0; j < bitmap.width(); ++j) {
+                auto const color = bitmap.get_pixel(j, i);
+
+                row[j * 3 + 0] = color.red();
+                row[j * 3 + 1] = color.green();
+                row[j * 3 + 2] = color.blue();
+            }
+
+            TRY(output.write_until_depleted(row.span()));
+        }
+
+        return {};
+    }
+
     for (int i = 0; i < bitmap.height(); ++i) {
         for (int j = 0; j < bitmap.width(); ++j) {
             auto color = bitmap.get_pixel(j, i);
-            if (options.format == Options::Format::ASCII) {
-                TRY(output.write_formatted("{} {} {}\t", color.red(), color.green(), color.blue()));
-            } else {
-                TRY(output.write_value(color.red()));
-                TRY(output.write_value(color.green()));
-                TRY(output.write_value(color.blue()));
-            }
+            TRY(output.write_formatted("{} {} {}\t", color.red(), color.green(), color.blue()));
         }
-        if (options.format == Options::Format::ASCII)
-            TRY(output.write_value('\n'));
+        TRY(output.write_value('\n'));
     }
 
     return {};